Lithium ion secondary batteries are classified into polygonal secondary batteries, cylindrical secondary batteries, and pouch secondary batteries according to their external structure.
In particular, a pouch secondary battery includes an electrode assembly and a pouch surrounding the electrode assembly, and is assembled as a battery pack by further including a protection circuit module and a case.
The present invention provides a secondary battery including an electrode tab that cannot be easily deformed by an external load, by forming a bending line or a protrusion in the electrode tab of the secondary battery and thereby increasing the rigidity of the electrode tab.
The present invention is not limited to the above-mentioned object, and those skilled in the art can clearly understand other unmentioned objects of the present invention.
According to the present invention, deformation of an electrode tab due to an external load and deviation of the electrode tab from a proper position can be prevented by bending the electrode tab in various shapes and thereby increasing the rigidity of the electrode tab.
Therefore, contact error can be prevented when the electrode tab makes contact with a pre-charger during a pre-charging operation of the secondary battery and welding error can be minimized between a terminal of a protection circuit module and the electrode tab when the electrode tab is welded to the protection circuit module.
Details of the following embodiments of the present invention are contained herein and in the accompanying drawings. The characteristics of the present invention and methods for achieving them will be apparent with reference to the embodiments of the present invention that will be described in detail with reference to the drawings. The same reference numerals are used throughout the specification to refer to the same or like elements.
Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Although a pouch secondary battery is described in embodiments of the present invention, it is apparent that the spirit of the present invention is not limited thereto.